This invention is concerned with improvements in and relating to syringes, particularly to syringes for use in medicine for applying more or less viscous materials, such as bone cements, to a desired site.
Basically, such a syringe comprises a barrel for containing material to be dispensed, a delivery tube or nozzle attached to one end of the barrel, a piston movably mounted in the barrel for forcing material contained in the barrel from the barrel to and through the delivery tube, and means for actuating the piston. Such syringes may have a disposable barrel, piston, and delivery tube since it is thereby possible to provide these elements of the syringe, which come into contact with the material to be dispensed in a pre-sterilized form. It is with this form of syringe that the present invention is concerned.
One problem which is encountered with conventional syringes of this type is that not all the material placed into the syringe is dispensed, since after the piston has been moved the length of the barrel, an appreciable amount of material may remain in the delivery tube which is commonly of some length, for example from 3 to 6 inches (7.5-15 cms).